New UHF install

[Tycho]

Out here in New Zealand we use UHF radios operating on 477MHz whcih sounds pretty similar to the FRS band in the States. Sick of recharging the little hand held and the poor reception I sprung for a GME TX3100. Very small 5W unit that can be mounted just about anywhere. Went with a half wavelength ground plane independent antenna (only 13 inches long). Biggest problem was deciding where to mount the antenna. Due to its short length wanted to keep it up above body panel work if I could. Ended up near the rear of the hood. The two pop rivets are into the fairly thin side panel (no access for backing plate etc) so I drilled and taped into the more substantial metal running around the top of the JK engine bay. A modified semi flexible faucet washer and a couple of normal washers later and it was braced. Bit of a 90 degree bend to the stock mount bracket and a hole for screw driver access and she was all done. Pretty happy with the end result and due for a test run this Easter.

[Roger]

Interesting.

Who makes the radio? Is GME part of the model number or is that manufacturer?
How many channels?
Is it simplex only or are there repeaters you can access?
You said 5 watts, I'm wondering why the massive heat sink for such a low wat output? I wonder if it is modifyable for a higher watt output.

[OU812]

Heres some more info on that radio.

http://www.gme.net.au/public/pdf/man...x3100_2_im.pdf

ENVIRONMENTAL
T emperature Range: -10°C to +60°C
ELECTRICAL
General
Compliant Specification: AS/NZS 4365
Frequency Range: 476.425-477.4 MHz
N umber of Channels: 40 UHF CB
Channel Spacing: 25 kHz
O peration Mode: Simplex channels 1-40
Semi Duplex channels 1‑8.
Scanning Speed: 20 channels per second
Antenna Impedance: 50 Ohms nominal
O perating Voltage Range: 10-15 Volts DC
N ominal Battery Voltage: 13.8 Volts DC
O ver Voltage Protection: 25 Volts DC max. At 18 Volts DC the
RF power is reduced, and the words
‘Hi DC’ flash.
O ver Current Protection: In-line 2A Fuse
Reverse Polarity Protection: Shunt Diode
Frequency Stability: ±5 PPM
Transmitter
RF Output: 5.0 Watts max.
Modulation: FM
Maximum Deviation: < ± 5 kHz at + 20 dB limiting
Spurious Emissions: < - 70 dBc
T ransmit Frequency
Response: + 6 dB per octave
300 Hz to 3 kHz + 1-3 dB.
Audio Signal to Noise: > 45 dB
Current Consumption: 1.5 Amps with 50 Ohm termination
Receiver
Circuit Type: Double Conversion Superheterodyne
Intermediate Frequencies: 1st - 21.4 MHz
2nd - 450 kHz
Current Consumption: < 180 mA muted
600 mA @ max. A.F output
Sensitivity: - 123 dBm for 12 dB SINAD
unweighted
Selectivity: - 6 dB at + 7.5 kHz
‑ 70 dB at ± 25 kHz
Intermodulation Immunity: 73 dB
Blocking Immunity: 100 dB
Spurious Response
Immunity: 70 dB
Audio Power: 3 Watts average into 4 Ohms
Audio Signal to Noise: > 45 dB
Receive Frequency
Response: ‑ 6 dB/Octave de‑emphasis
300 Hz to 3 kHz + 1-3 dB
Conducted Spurious
Emission: < - 57 dBm
MECHANICAL
Dimensions: 102 (W) x 87 (D) x 23 (H) mm
Weight: 158 grams
Shock and Vibration: MIL STD 810 method

[Tycho]

Gme

Yup GME is an Australian manufacturer. Do both marine and land based communications. Seem to be pretty cutting edge and I am very impressed with the signal quality out of the unit. The receiver/antenna is great. I went for a drive from home and could still pick up my partner, Liz who was on a little 1/2 watt handheld about 2 miles away through a built up area. Can't wait to see how it goes with another similar unit in another truck.